glassbox.json

{
  "slug": "breadclear",
  "box": 120,
  "date": "2026-10-10",
  "title": "BreadClear",
  "question": "How is bread made?",
  "hook": "Bread is flour, water, yeast and salt, plus three hidden events. Kneading turns two proteins into a stretchy net. A living fungus blows it full of gas. And in the oven the wet inside can never pass 100 °C, while the dry crust browns at 150 °C. Knead, proof and bake a loaf yourself, and see why the fridge makes it stale.",
  "thumbText": "HOW BREAD IS MADE",
  "field": "chemistry",
  "minutes": 15,
  "tags": [
    "bread",
    "gluten",
    "yeast",
    "fermentation",
    "proofing",
    "baking",
    "maillard reaction",
    "atta",
    "maida",
    "roti",
    "naan",
    "pav",
    "sourdough",
    "food science",
    "three.js"
  ],
  "explainer": [
    {
      "title": "It starts in a wheat grain",
      "text": "A wheat grain is a bran coat (about 14.5% of its weight), a tiny germ (2.5%) and a starchy endosperm (83%). Atta is the whole grain ground. Maida is the endosperm alone. Both have about the same protein, but atta has about four times the fibre."
    },
    {
      "title": "Kneading builds gluten",
      "text": "Add water and two flour proteins, glutenin and gliadin, link into gluten. Kneading stretches the tangle of chains into thin, springy sheets. When a pinch of dough stretches thin enough to let light through, the windowpane test, the net is ready to hold gas."
    },
    {
      "title": "Yeast blows the bubbles",
      "text": "Baker's yeast is a living fungus, 8 to 10 billion cells in a gram. It splits sugar into carbon dioxide and alcohol, about half a gram of each from a gram of sugar. The gas inflates tiny air cells that kneading folded in. Yeast works fastest near 35 °C and dies by about 55 to 60 °C."
    },
    {
      "title": "Proofing is a race",
      "text": "Warmth and more yeast speed the rise. Salt, about 2% of the flour, slows it and tightens the gluten. A standard dough doubles in about an hour at 27 °C and takes many hours in the fridge. Wait too long and the bubble walls tear: the dough collapses, over-proofed."
    },
    {
      "title": "The oven sets it from the outside in",
      "text": "In the first minutes the loaf springs up by as much as a quarter. Near 60 °C the yeast dies, and from 60 to 80 °C the starch swells and sets into crumb. The wet inside can never pass 100 °C. Only the dried crust climbs to about 150 °C, where the Maillard reaction turns it brown."
    },
    {
      "title": "Stale is not dry",
      "text": "Bread goes stale because its starch slowly re-crystallises and squeezes out water, fastest just above freezing. So the fridge is the worst place for it and the freezer the best. Sourdough rises with wild yeasts and bacteria, naan with yeast or curd, and roti with nothing but steam."
    }
  ],
  "concepts": [
    {
      "term": "Endosperm",
      "def": "The starchy inside of the wheat grain, about 83% of its weight. Maida is ground endosperm; atta is the whole grain."
    },
    {
      "term": "Gluten",
      "def": "The stretchy network formed when the wheat proteins glutenin and gliadin are wetted and kneaded. It traps the gas that raises bread."
    },
    {
      "term": "Windowpane test",
      "def": "Stretching a pinch of dough into a sheet. If light shows through before it tears, the gluten is developed."
    },
    {
      "term": "Fermentation",
      "def": "Yeast splitting sugar into carbon dioxide and ethanol: C6H12O6 → 2 C2H5OH + 2 CO2."
    },
    {
      "term": "Proofing",
      "def": "Resting a yeast dough so the gas can raise it. Too long and it over-proofs: the bubble walls tear and it falls."
    },
    {
      "term": "Oven spring",
      "def": "The quick rise in the first minutes of baking, before the yeast dies and the crust sets."
    },
    {
      "term": "Gelatinisation",
      "def": "Starch granules taking up water, swelling and setting into a gel at about 60 to 80 °C. It turns dough into crumb."
    },
    {
      "term": "Maillard reaction",
      "def": "Sugars and amino acids reacting in dry heat, from roughly 140 to 150 °C, to make the brown colour and smell of crust."
    },
    {
      "term": "Retrogradation",
      "def": "Gelatinised starch slowly re-crystallising as bread ages. The main cause of staling, and fastest in the fridge."
    }
  ],
  "links": {},
  "storage": [
    {
      "key": "breadclear.v1",
      "what": "Which chapters you have opened, your best quiz scores, and sound on or off."
    }
  ],
  "credits": [
    {
      "name": "three.js",
      "license": "MIT",
      "url": "https://threejs.org"
    },
    {
      "name": "Geist, Instrument Serif",
      "license": "SIL OFL 1.1",
      "url": "https://openfontlicense.org"
    }
  ]
}